The present invention relates to railway tank cars and, in particular, to manifolded tank cars which may be interconnected to accommodate loading or unloading of the entire group of interconnected cars without movement thereof from a single point therealong, thereby acccommodating consecutive loading, transporting and unloading of fluid ladings and facilitating the formation of unit trains.
The concept of providing fluid communication among a series of interconnected railway tank cars is disclosed in the prior art but previous systems have failed to provide an intertank connection arrangement which insured safe handling of the fluid ladings during transportation. For example, U.S Pat. No. 1,542,116, issued to R. Welcker, discloses railway tank cars for interconnection in a manifolded arrangement to accommodate continuous emptying of the interconnected tanks from a single location, without moving or disconnecting the cars. However, Welcker's arrangement does not provide for continuous loading of the interconnected tanks from a single location, and the intertank lading connections are along the longitudinal axes of the tanks which has been found to be a disadvantageous arrangement.
U.S. Pat. No. 3,722,556, issued to William Jeffers et al., discloses a manifolded tank car arrangement which accommodates both loading and unloading of a string of interconnected tank cars from a single location, but Jeffers et al. provide the intertank lading connections at the bottoms of the tanks. Further, Jeffers et al. do not provide a lading conduit which during loading automatically determines the final outage of the lading in the tank, a feature which is critically necessary with certain bulk lading commodities to accommodate product expansion in transit.
U.S. Pat. No. 3,675,670 issued to Osamu Ogawa, discloses interconnected tank cars which require external piping for drainage and externally mounted valves. These features are disadvantageous for in the first case added material cost is involved while in the second case a hazardous situation could arise in case of a train wreck.